First of all an 8 month old BMW shouldn't need 4 wheel alignment unless it has had some work done on the suspension, which it shouldn't have at that age and even if it had BMW would have realigned the suspension after anyway. Unless of course the car had hit a curb or two.
The tyre pressures that you mentioned are the same as they recommend for my car which is on 16's. I have found that increasing the front to 34 and the back to about 36 gives me sharper handling.
To some extent the steering that you describe, or tramlining as it is also known, where the cars tries to follow the camber of the road, is a problem that BMWs suffer from. I found that fitting non-directional tyres helped out a lot with this problem, but other than that all I can say is that you will get used to it.
If you are concerned you could take it back to the dealer where you bought it and ask them whether it should feel like it does.